环境侵蚀对混凝土结构力学损伤效应研究

Study on mechanical damage effect of environmental erosion on concrete structures

为了研究酸性干湿循环作用对混凝土结构力学损伤影响,根据不同酸性环境(pH值为3、5、7)条件以及不同干湿循环次数(N=0、5、10、20、50)作用下,通过对混凝土试件进行质量损失测试以及抗压强度、抗折强度试验等,对酸性干湿循环作用引起混凝土结构力学损伤效应进行定量分析。研究结果表明:环境侵蚀对混凝土结构以及强度产生不可逆损伤,随着酸性干湿循环次数的增加,质量损失率最大达到9.30%、抗压、抗折强度最大增幅分别为13.58%、15.40%,最大减小幅度分别为9.55%、10.55%;混凝土抗压、抗折强度呈现分段变化,符合线性变化及指数变化规律;建立混凝土质量损失率、抗压强度以及抗折强度损伤演化方程,对环境侵蚀引起的混凝土结构力学损伤进行定量表征。

In order to study the effect of acid wet and dry cycle on the mechanical damage of concrete structure,according to different acidic environment(pH=3,5,7)and different number of dry and wet cycles(N=0,5,1 0,2 0,5 0),the damage effect of concrete structure caused by acid dry and wet cycle was quantitatively analyzed by the test of mass loss and compressive strength and flexural strength test on concrete specimens.The results showed that the environmental erosion has irreversible damage to the concrete structure and strength,and with the increase of acid dry and wet cycle tim es,the maximum mass loss rate was 9.30%,and the maximum increase of compressive strength and flexural strength were 13.5 8%,15.4 0%,respectively the maximum reduction ranges were 9.5 5%,10.5 5%.The compressive and flexural strength of concrete presents piecewise changes,which conformed to the linear and exponential change rules.The damage evolution equation of concrete mass lo ss,compressive strength and flexural strength were established,and the mechanical damage of concrete structure caused by environmental erosion was quantitatively characterized.